A friend of mine just lost his save file on his copy of pokemon crystal that had pretty much everything legit along with 8 shiny pokemon (again legit) and both of us are a little frightened to see some of our other saves die (dragon warrior 3 gbc with all the silver and most of the gold medals for example!) anyways, i have some of those old shitty brainboy things that can back them up, but no way to get them to another device, so yeah..no good there, I also have a device that can alegedly backup gbc ps1 and dc saves, but requires a serial cable (which my computer doesn't have a port)

so what i'm asking is there an afordable way to backup these cartidges on newer hardware before the batteries eventualy fail?